Multiple finger electrical contact and method of making the same



w. HUPPERT 2,248,675

MULTIPLE FINGER ELECTRICAL CONTACT AND METHOD OF MAKING THE SAME July 8,1941.

Filed Oct; 24, 1939 INVENTOR w/fiawr Hufifier'f.

BY v

, ATTORNEY Patented July 8 1941 IVIULTIPLE FINGER ELECTRICAL CONTACT ANDMETHOD OF MAKING THE. SAME William Huppert, New York, N. Y. IApplication October- 24, 1939, Serial No. 300,939

8 Claims.

This invention relates to a multiple finger electrical contact andmethod of making the same, and more particularly to contacts for use inmultiple outlets adapted to receive two or more plugs for makingconnection with various electrical attachments or appliances.

A form of such multiple outlet is shown and described in my Patent No.1,818,804 of August 11, 1931. That outlet contains two contact memberseach having a terminal connected to one of the feed lines and eachhaving two or more diverging resilient contact fingers for makingconnection with the prongs of the plugs. One of the fingers makescontact with a prong of one plug and the other makes contact with aprong of another plug, both on the same side of the feed line.

Heretofore such multiple contacts have generally been made of two ormore pieces of conductor metal riveted or otherwise secured together.This has materially increased the cost of production.

It has also been proposed to make single piece contacts by stamping themfrom a fiat blank of conductor metal with the contact fingers disposedin angular relation to each other, the portion of the blank between thefingers being cut out. However, this manner of manufacture isobjectionable since it results in an excessive waste of material.

One of the objects of this invention is to produce one piece multiplefinger contacts of the character described with a minimum waste ofmaterial. Another object isto provide multiple finger contacts havingintegral terminal portions, made of a single piece of metal, ofsimplified construction, and which are inexpensive to manufacture.

A further object is to provide a novel method of bending the blanks intoshape whereby the contact fingers, originally stamped out in parallelrelation, are spread apart in the required angular relation to fitproperly into the outlet casing.

A-feature of the invention is that the arrangement of the terminal andfinger portions of the contacts is such that the height of the outletcasing with which they are used may be appreciably reduced, thusefiecting an economy in cost of the completed outlet.

The foregoing, as well as other novel features of the invention, willappear more fully from the following description thereof, referencebeing had to the accompanying drawing, in which- Figure 1 is a face viewof a fiat blank for a two finger contact;

Fig. 2 is a perspective view of the contact in an intermediate step inthe process of its formation; Fig. 3 is a perspective View of thecompleted contact;

Fig. 4 is a bottom view of a multiple outlet with the insulating diskpartly broken awayto show the contact in place;

Fig. 5 is a cross-section on the line 5-5 of Fig.

Fig. 6 shows a modification of the blank; and. Fig. '7 is a perspectiveView of a modified form of contact.

In making a two finger contact member, a blank ID of suitable shape,such for example as shown in Figure 1, is formed or stamped from a fiatstrip or sheet of brass, copper, or, other conductor metal. The blanksare preferably stamped out lengthwise of the metal strip or sheet sothat the contact fingers will extend in the direction of the grain ofthe material. This provides a-construction in which the contact fingershave increased and more durable resiliency. 1 The lower portion of theblank. is divided into I two separate fingers H and I2 by a slit orcutl3 that. extends longitudinally of the blank upward to the point l4.Since the overall width of the lower portion of the blank issubstantially that of thetwo separate fingers combined,practically-nomaterial is wasted in stamping out the fingers.

The upper portion of the blank, when it has been bent to shape as shownin Figs. 2 and3, forms the terminal portion N3 of the finished contactmember. A hole l6 may be formed in'the terminal portion for reception ofa binding or terminal screw. I-Iowever,,other means for attachingthefeed wire to the terminal may be employed.

The terminal portion |5 is bent back out of the plane of the fingerportion along a transverse line H as shown in Fig. 2. It will be notedthat'the u per end Id of the dividing line l3 extends up to this line ofbend. The contact fingers H and I2 may themselves eachbe doubledover-"along a transverse line l2. to provide increased resiliency:however, such bending is not essential. The side edges of the terminalportion may be bent up as seen in Figs. 2 and 3.

The final step in forming the finished contact member shown in Fig. 3 isto bend or crimp the terminal portion l5 downwardly, in an angular bend,along the longitudinal center lineywhich line is indicated by thenumeral I8in Fig. '1 and is in line with slit l3. This bending operationcauses the two contact fingers I l' and I2 to spread apart at an angleto each other. The relationship between this angular bend and the spreadof the fingers is such that the sum of the two angles is always 180. Forinstance, if it is desired to spread the contact fingers at an angle of60 then the angularity of the applied bend or crimp would be 120.

This final bending operation is an important feature of the invention asit permits of forming, without waste of material, a one piece contactmember having contact fingers that diverge angularly from'each other.

In the finished form of the contact member the point of the anglebetween the contact fingers falls directly in the line of the front edgell of the terminal portion [5, as seen in Fig. 3.

An outlet in which the contact members may be used is shown in Figs. 4and 5; The outlet.

comprises a shell or casing P9 of insulating material, preferably amolded plastic. The outlet is designed to receive two standard plugs(not shown). The casing houses two contact members each seated in arecess. One feed wire is connected 'to'the terminal portion '5 of eachcontact by a binding screw 2| or other suitable means. The casing hasapertures 22 into which the prongs of the plugs are inserted to makecontact with the contact fingers l l and I2. 23 is a cover disk ofinsulating fibre which is held in place by a screw 24.

It will be apparent that the prongs of the plugsmay be inserted to theirfull extent into the openings-220i the outlet casing withoutinterference with the terminal portions l5 of the contact members. Thispermits of a considerable reduction in'the height of the casing Withoutimpairing theefiiciency'of the contact between the contactfin gers' andthe prongs.

A inodific'atienof the invention is illustrated in Figs; '6 and 7wherein is shown a contact member having three contact fingers for usein an outlet designed to accommodate three plugs. In this instance theblank 25 is formed with three contact fingers 26, 21 and Z8, and aterminal portion 29. The fingers are separated by cuts or slits 3 0 thatextend upwardly to points 3|. The contact fingers may eachbe bent overon the line 32 and the terminal portion may be bent back en the line'33l"In the"fi nal bending operation, the terminal portion is bent orcrimped at an angle along each of the lines i fi and 35 to separatethetwoouter contact fingers from themiddle one, as seen in Fig. 7.

The side edges of the terminal portion may be formed with sharp teeth 36to provide a prick point contact with the feed line.

Various modifications in the construction and method of manufactureherein described may be made by those skilled in the art withoutdeparting fromthe scope of the invention as defined in the claims.

' What I claim is:

IL A method of making a one piece multiple finger electrical contact,which comprises forming froma fiat piece of conductor metal a blankhaving a terminal portion and a finger portion, diwding the fingerportion lengthwise into a plurality of separate fingers, bending theblank transversely along a line between the terminal and fingerportionsfand spreading the fingers to a desired angle by bending theterminal portion longitudinally.

V 2. A method of making a one piece multiple finger electrical contactwhich comprises forming from a flat piece of conductor metal a blankhaving a terminal portion and a finger portion, dividing the fingerportion lengthwise into a plurality of separate fingers, the width ofthe finger portion of the blank being substantially equal to thecombined widths of the separate fingers, bending the blank transverselyalong a line between the terminal and finger portions, and spreading thefingers to a desired angle by bending the terminal portionlongitudinally.

3. A method of making a one piece multiple finger electrical contact,which comprises stamping out longitudinally from a flat piece ofconductor metal a blank having a terminal portion and a finger portion,bending the blank transversely along a line between the terminal andfinger portions, and spreading the fingers to a desired angle by bendingthe terminal portion longitudinally.

4. A method of making a one piece multiple finger electrical contact,which comprises forming from a flat piece of conductor metal a blankhaving a terminal portion and a finger portion, dividing the fingerportion lengthwise into a plurality of separate fingers, bending theblank transversely along a line between the terminal and fingerportions, and spreading the fingers to a desired angle by bending theterminal portion longitudinally along a line which is a continuation ofthe line of separation of the fingers.

5. A method of making a one piece multiple finger electrical con-tact,which comprises forming from a flat piece of conductor metal a blankhaving a terminal portion and a finger portion, separating the fingerportion lengthwise to form a plurality of individual fingers, bendingthe terminal portion back out of the plane of the finger portion,doubling over the finger portion, and spreading the fingers'by bendingthe terminal portion longitudinally downward at an angle.

6. A one piece multiple finger electrical contact comprising a metalblank having a terminal portion and a finger portion, the finger portionbeing divided longitudinally into a plurality of substantially parallelcontact fingers, said contact fingers being bent downwardly from theterminal portion and spread apart at an angle to each other.

'7. A one piece multiple finger electrical contact comprising a metalblank having a terminal portion and a finger portion, the finger portionbeing divided longitudinally into a plurality of substantially parallelcontact fingers, the contact fingers being bent downwardly from theterminal portion and spread apart at an angle to each other, the grainof the contact fingers having the same relationship to theirlongitudinal axes as the grain of the terminal portion has to itslongitudinal axis.

8. A one piece multiple finger electrical contact comprising a metalblank having a terminal portion and a finger portion, the finger portionbeing divided longitudinally into a plurality of .contact fingers, saidterminal portion having a transverse angular bend, the contact fingersbeing bent downwardly from the terminal portion and spread apart at anangle to each other, the relationship between transverse angular bend ofthe terminal portion and the angle that the contact fingers make witheach other being such that the sum of the two angles is WILLIAM HUPPERT.

